/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;

/**
 * This ConstantVisitor adds all constants that it visits to the constant pool of a given target class.
 *
 * Bootstrap methods attributes are automatically updated for invokedynamic constants.
 *
 * @author Eric Lafortune
 */
public class ConstantAdder implements ConstantVisitor {
    private final ConstantPoolEditor constantPoolEditor;
    private final BootstrapMethodsAttributeAdder bootstrapMethodsAttributeAdder;

    private int constantIndex;

    /**
     * Creates a new ConstantAdder that will copy constants into the given target class.
     */
    public ConstantAdder(ProgramClass targetClass) {
        constantPoolEditor = new ConstantPoolEditor(targetClass);
        bootstrapMethodsAttributeAdder = new BootstrapMethodsAttributeAdder(targetClass);
    }

    /**
     * Adds a copy of the specified constant in the given class and returns its index. If the specified index is 0, the
     * returned value is 0 too.
     */
    public int addConstant(Clazz clazz, int constantIndex) {
        clazz.constantPoolEntryAccept(constantIndex, this);

        return this.constantIndex;
    }

    /**
     * Adds a copy of the given constant in the given class and returns its index.
     */
    public int addConstant(Clazz clazz, Constant constant) {
        constant.accept(clazz, this);

        return this.constantIndex;
    }

    /**
     * Returns the index of the most recently created constant in the constant pool of the target class.
     */
    public int getConstantIndex() {
        return constantIndex;
    }

    // Implementations for ConstantVisitor.

    public void visitIntegerConstant(Clazz clazz, IntegerConstant integerConstant) {
        constantIndex = constantPoolEditor.addIntegerConstant(integerConstant.getValue());
    }

    public void visitLongConstant(Clazz clazz, LongConstant longConstant) {
        constantIndex = constantPoolEditor.addLongConstant(longConstant.getValue());
    }

    public void visitFloatConstant(Clazz clazz, FloatConstant floatConstant) {
        constantIndex = constantPoolEditor.addFloatConstant(floatConstant.getValue());
    }

    public void visitDoubleConstant(Clazz clazz, DoubleConstant doubleConstant) {
        constantIndex = constantPoolEditor.addDoubleConstant(doubleConstant.getValue());
    }

    public void visitPrimitiveArrayConstant(Clazz clazz, PrimitiveArrayConstant primitiveArrayConstant) {
        constantIndex = constantPoolEditor.addPrimitiveArrayConstant(primitiveArrayConstant.getValues());
    }

    public void visitStringConstant(Clazz clazz, StringConstant stringConstant) {
        constantIndex = constantPoolEditor.addStringConstant(stringConstant.getString(clazz),
            stringConstant.referencedClass, stringConstant.referencedMember);
    }

    public void visitUtf8Constant(Clazz clazz, Utf8Constant utf8Constant) {
        constantIndex = constantPoolEditor.addUtf8Constant(utf8Constant.getString());
    }

    public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) {
        // Find the bootstrap methods attribute.
        AttributesEditor attributesEditor = new AttributesEditor((ProgramClass)clazz, false);

        BootstrapMethodsAttribute bootstrapMethodsAttribute =
            (BootstrapMethodsAttribute)attributesEditor.findAttribute(ClassConstants.ATTR_BootstrapMethods);

        // Add the name and type constant.
        clazz.constantPoolEntryAccept(invokeDynamicConstant.u2nameAndTypeIndex, this);

        // Copy the referenced classes.
        Clazz[] referencedClasses = invokeDynamicConstant.referencedClasses;
        Clazz[] referencedClassesCopy = null;
        if (referencedClasses != null) {
            referencedClassesCopy = new Clazz[referencedClasses.length];
            System.arraycopy(referencedClasses, 0, referencedClassesCopy, 0, referencedClasses.length);
        }

        bootstrapMethodsAttribute.bootstrapMethodEntryAccept(clazz,
            invokeDynamicConstant.getBootstrapMethodAttributeIndex(), bootstrapMethodsAttributeAdder);

        // Then add the actual invoke dynamic constant.
        constantIndex = constantPoolEditor.addInvokeDynamicConstant(
            bootstrapMethodsAttributeAdder.getBootstrapMethodIndex(), constantIndex, referencedClassesCopy);
    }

    public void visitMethodHandleConstant(Clazz clazz, MethodHandleConstant methodHandleConstant) {
        // First add the field ref, interface method ref, or method ref
        // constant.
        clazz.constantPoolEntryAccept(methodHandleConstant.u2referenceIndex, this);

        // Then add the actual method handle constant.
        constantIndex =
            constantPoolEditor.addMethodHandleConstant(methodHandleConstant.getReferenceKind(), constantIndex);
    }

    public void visitModuleConstant(Clazz clazz, ModuleConstant moduleConstant) {
        constantIndex = constantPoolEditor.addModuleConstant(moduleConstant.getName(clazz));
    }

    public void visitPackageConstant(Clazz clazz, PackageConstant packageConstant) {
        constantIndex = constantPoolEditor.addPackageConstant(packageConstant.getName(clazz));
    }

    public void visitFieldrefConstant(Clazz clazz, FieldrefConstant fieldrefConstant) {
        // First add the referenced class constant, with its own referenced class.
        clazz.constantPoolEntryAccept(fieldrefConstant.u2classIndex, this);

        // Then add the actual field reference constant, with its referenced
        // class and class member.
        constantIndex = constantPoolEditor.addFieldrefConstant(constantIndex, fieldrefConstant.getName(clazz),
            fieldrefConstant.getType(clazz), fieldrefConstant.referencedClass, fieldrefConstant.referencedMember);
    }

    public void visitInterfaceMethodrefConstant(Clazz clazz, InterfaceMethodrefConstant interfaceMethodrefConstant) {
        // First add the referenced class constant, with its own referenced class.
        clazz.constantPoolEntryAccept(interfaceMethodrefConstant.u2classIndex, this);

        // Then add the actual interface method reference constant, with its
        // referenced class and class member.
        constantIndex = constantPoolEditor.addInterfaceMethodrefConstant(constantIndex,
            interfaceMethodrefConstant.getName(clazz), interfaceMethodrefConstant.getType(clazz),
            interfaceMethodrefConstant.referencedClass, interfaceMethodrefConstant.referencedMember);
    }

    public void visitMethodrefConstant(Clazz clazz, MethodrefConstant methodrefConstant) {
        // First add the referenced class constant, with its own referenced class.
        clazz.constantPoolEntryAccept(methodrefConstant.u2classIndex, this);

        // Then add the actual method reference constant, with its referenced
        // class and class member.
        constantIndex = constantPoolEditor.addMethodrefConstant(constantIndex, methodrefConstant.getName(clazz),
            methodrefConstant.getType(clazz), methodrefConstant.referencedClass, methodrefConstant.referencedMember);
    }

    public void visitClassConstant(Clazz clazz, ClassConstant classConstant) {
        // Add the class constant, with its referenced class..
        constantIndex =
            constantPoolEditor.addClassConstant(classConstant.getName(clazz), classConstant.referencedClass);
    }

    public void visitMethodTypeConstant(Clazz clazz, MethodTypeConstant methodTypeConstant) {
        constantIndex = constantPoolEditor.addMethodTypeConstant(methodTypeConstant.getType(clazz),
            methodTypeConstant.referencedClasses);
    }

    public void visitNameAndTypeConstant(Clazz clazz, NameAndTypeConstant nameAndTypeConstant) {
        constantIndex = constantPoolEditor.addNameAndTypeConstant(nameAndTypeConstant.getName(clazz),
            nameAndTypeConstant.getType(clazz));
    }
}
